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Chapter 042. Gastrointestinal Bleeding (Part 5)

LOWER GIB (Fig. 42-2) Patients with hematochezia and hemodynamic instability should have upper endoscopy to rule out an upper GI source before evaluation of the lower GI tract. Patients with presumed LGIB may undergo early sigmoidoscopy for the detection of obvious, low-lying lesions. However, the procedure is difficult with brisk bleeding, and it is usually not possible to identify the area of bleeding. | Chapter 042. Gastrointestinal Bleeding Part 5 LOWER GIB Fig. 42-2 Patients with hematochezia and hemodynamic instability should have upper endoscopy to rule out an upper GI source before evaluation of the lower GI tract. Patients with presumed LGIB may undergo early sigmoidoscopy for the detection of obvious low-lying lesions. However the procedure is difficult with brisk bleeding and it is usually not possible to identify the area of bleeding. Sigmoidoscopy is useful primarily in patients 40 years with minor bleeding. Figure 42-2 Suggested algorithm for patients with acute lower gastrointestinal bleeding. Sequential recommendations under Hemodynamic instability assume a test is found to be nondiagnostic before next test is performed. Some suggest colonoscopy for any degree of rectal bleeding in patients 40 years as well. fIf massive bleeding does not allow time for colonic lavage proceed to angiography. Tc-RBC 99mtechnetium-labeled red blood cell. Colonoscopy after an oral lavage solution is the procedure of choice in patients admitted with LGIB unless bleeding is too massive or unless sigmoidoscopy has disclosed an obvious actively bleeding lesion. 99mTc-labeled red cell scan allows repeated imaging for up to 24 h and may identify the general location of bleeding. However radionuclide scans should be interpreted with caution because results especially from later images are highly variable. In active LGIB angiography can detect the site of bleeding extravasation of contrast into the gut and permits treatment with intraarterial infusion of vasopressin or embolization. Even after bleeding has stopped angiography may identify lesions with abnormal vasculature such as vascular ectasias or tumors. GIB OF OBSCURE ORIGIN Obscure GIB is defined as persistent or recurrent bleeding for which no source has been identified by routine endoscopic and contrast x-ray studies it may be overt e.g. melena hematochezia or occult. Push enteroscopy with a specially designed enteroscope